Vomiting-related emergency department visits in Colorado rose from 119,312 in 2013 to 153,699 in 2018, with additional recreational dispensaries associated with increased visit rates.
Emergency physicians, public health officials, cannabis policymakers, and healthcare administrators.
29% increase in vomiting-related ER visits over 5 years post-legalization
What the researchers found
Vomiting-related ED visits increased 29% over the study period. Each additional recreational dispensary was associated with a 3% increase in vomiting-related visits (IRR 1.03). However, counties with high baseline medical dispensary exposure experienced smaller increases than counties with no prior dispensaries (IRR 0.97).
Why it matters
This large-scale analysis provides population-level evidence connecting cannabis market expansion to increased vomiting-related healthcare utilization, likely reflecting cannabinoid hyperemesis syndrome.
The numbers in context
Total patients: 820,778. Visits 2013: 119,312. Visits 2018: 153,699. Increase: 29%. Recreational dispensary IRR: 1.03. Counties with prior medical dispensaries grew 5.8% slower. Female: 62%. Ages 0-18: 25%.
How the study worked
Cross-sectional analysis of 820,778 patients with vomiting-related ED claims reported to the Colorado Hospital Association from January 2013 to December 2018, examining the relationship between dispensary density and visit rates by county.
What this study cannot tell us
Cannot confirm cannabis as the cause of vomiting. ED claims data may include multiple visits by the same patient. No direct measure of cannabis use among patients presenting with vomiting.
How to read the evidence
Large population-level dataset with county-level dispensary data, but cannot directly link individual vomiting cases to cannabis use.
When this study was published
Published in 2021 using Colorado data from 2013-2018.
The bigger picture
The finding that counties with established medical dispensaries saw slower increases suggests a possible habituation or education effect in markets with longer cannabis exposure.
Questions still open
- Is the slower growth in counties with established dispensaries due to clinician awareness, consumer education, or demographic differences? What proportion of these vomiting visits are actually CHS?
Common questions
Did cannabis legalization increase ER visits for vomiting?
Did areas with existing medical marijuana dispensaries see the same increase?
Read the original research
Changes in Emergency Department Encounters for Vomiting After Cannabis Legalization in Colorado.
JAMA network open, 4(9), e2125063
Citation
Wang, George Sam; Buttorff, Christine; Wilks, Asa; Schwam, Daniel; Tung, Gregory; Pacula, Rosalie Liccardo. (2021). Changes in Emergency Department Encounters for Vomiting After Cannabis Legalization in Colorado.. JAMA network open, 4(9), e2125063. https://doi.org/10.1001/jamanetworkopen.2021.25063